Health and Safety

Busted, Busted, and Some More Information

Sometimes it's not easy being a Health and Safety column
editor. I had a rough October.

First, at the WAAC Annual Meeting, there was the searing
question—"In that slide of you pressure washing that mural, were
you wearing safety goggles?"

Busted. Guilty. And shamed because it never occurred to me, your
WAAC Health and Safety column editor, that I should wear eye protection while
pressure washing a mural. Of course I should have been wearing goggles. It was
so obvious, so glaring, so wrong. Suffice it to say, I will never pressure wash
(or pressure anything for that matter) in the future without safety goggles
securely planted over my baby blues.

Discussing my shame at the WAAC board dinner, WAAC VP, Mitchell
Hearns Bishop noted that often people who wear glasses overlook eye protection.
Not on a conscious level, but at a more primal level. Kind of in a reverse
Pavlov's dog sort of way. Those occasional everyday occurrences where
things head towards your face and you instinctively flinch. Those of us who wear
glasses flinch just the same, but are often greeted by the reassuring sound of
"click" as the offending whatever bounces off a lens.

Which kind of brings up the question, at least for those
conservators saddled with glasses: What type of lens should I get? My
recommendation is still polycarbonate. According to the Polycarbonate Lens
Council information site (probably not altogether impartial) it is the most
shatter resistant specular lens material. It is already "high index"
so it works well for heavier prescriptions. Polycarbonate is also the standard
for safety goggles.

Polycarbonate lenses are also said to be UV (ultraviolet
radiation) absorbing and opticians will tell you that there is no need to add UV
filtering to the lenses. This claim is also made by the Polycarbonate Lens
Council. And I have recommended in previous columns that wearers of
polycarbonate lenses probably don't need to wear additional eye protection
when working with long-wave ultraviolet light.

Of course, it's not that simple. Testing my lenses with a
UV light meter, I found that the level of UV transmitted was much higher than I
would have expected for a "UV filtering" material. I sent an email
to the Polycarbonate Lens Council some weeks ago asking about this observation
and have not yet received a reply. I checked some other eyeglasses with the same
meter and found that some lenses do indeed block almost all of the UV present in
direct sunlight.

[As an aside, I've found similar conflicts between claims
of UV filtering in

laminated window glass and actual measured UV levels. In the
case of polyvinyl butylral, the laminating agent, the polymer is not inherently
UV absorbing. It is modified with light stabilizers which absorb the UV. The
product specification claims absorption of 99% of UV below 380nm however I have
measured UV levels with a Meaco Lux & UV Meter through these glasses with UV
transmissions from less than 1% to 14% to as high as 20%.]

I will look into the question of lens materials for a future
column. However, of possible interest and utility, The Polycarbonate Lens
Council offers a "UV Sensometer Card" which they provide for $4.95
shipping and handling. Intended to evaluate the UV protection of your present
glasses, the card appears to have a UV sensitive material that darkens on
exposure. By using the comparison chart you can determine the relative amount of
UV transmitted through your glasses. I've just mailed in my order so I
can't say if it really works, but this might be of some utility to
conservators trying to determine if glazing materials do indeed block UV. Hey,
you can even check out your eye glass lenses. [You can download the UV Card
Order Form from http://www.polycarb.org/uvorder.htm.]

Yet, I digress. Busted: Last issue, I mentioned an incident
where I inadvertently rolled a scaffolding into low-hanging, power lines.
Fortunately, there was no harm done beyond the scare and embarrassment. It was
really stupid. I try to keep the subjects covered in this column
rooted in the practical. I often discuss aspects of my own conservation practice
not merely to talk about myself, but to allow me to offer real world examples of
problems and solutions.

Monona Rossol, of Arts, Crafts and Theater Safety (ACTS) was
kind enough to send me a letter explaining the seriousness of the violation of
scaffold safety regulations I had committed.

She wrote that one is not allowed on a scaffold unless there is
a certificate-holding "competent" person present. This person must
be trained on all the regulations regarding scaffolding safety including those
relating to power lines. The competent person must survey the area and identify
any power lines and their voltage. This is also the person who would call the
power company and arrange to have them temporarily de-energized if the scaffold
would ever be anticipated to be within the distance allowed.

The clearance between scaffolds and powerlines shall be as
follows: Scaffolds shall not be erected, used, dismantled, altered, or moved
such that they or any conductive material handled on them might come closer to
exposed and energized power lines than as follows:

Insulated Line Voltage

Minimum Distance

Alternatives

Less than 300 volts

3 feet (0.9 m)

300 volts to 50 kv

10 feet (3.1 m)

More than 50 kv

10 feet plus 0.4 inches (1.0 cm) for each 1
kv over 50 kv

2 times the length of the line insulator,
but never less than 10 feet

Uninsulated Line Voltage

Minimum Distance

Alternatives

Less than 50 kV

10 feet

More than 50 kv

10 feet plus 0.4 inches for each 1 kv over
50 kv

2 times the length of the line insulator
but never less than 10 feet

Monona went on to state the need to impress on our profession
that conservators legally cannot get up on a scaffold without being directed by
a certificate-holding competent person. Conservators could take the necessary
training course to become the competent person. However, she points out that the
courses are tough, expensive, and you need to retrain annually.

Thank you, so very much Monona for writing. I will get my
scaffolding house in order. Everyone working on or with scaffolding should be in
compliance with the appropriate OSHA regulations, covered by CFR 1926.451 Safety
and Health Regulations for Construction: Subpart L—Scaffolds. It all is
available on-line at:
http://www.osha-slc.gov/OshStd_toc/OSHA_Std_toc_1926_SUBPART_L.html (note that
there are underscore characters between each word in the URL) and the sub-pages
following.

On a less grave note. Also in the last column, I flippantly said
"...Formica: I don't even know how to look that one up."
Fellow AIC Health and Safety committee member Mary W. Ballard, Senior Textiles
Conservator at SCMRE, the lab formerly-known-as-CAL, emailed the following note.
It's such great information that I can't resist publishing it
here.

Chris—in your WAAC article, you wrote you weren't
sure of the formula of Formica. It's a cross-linked melamine-formaldehyde
polymer resistant to most organic solvents. Somewhat effected by acids &
bases. I have learned & forgotten the synthesis several times over the years
but it's pretty easy: looks like a benzene ring with every other carbon
substituted with a nitrogen. It's called a triazine; it has the same
alternating double bonds as benzene. On each of the 3 carbons is a substituent
amino (NH2) group and get cross-linked by reacting with formaldehyde. Once
everything is reacted, it's pretty much a dense, unreactive polymer. This
chemistry is related to "durable press" resin, no iron cotton, and
also to the reactive/covalent bond in reactive dyes. Unless you wear only white
clothes, chances are the dyes of your clothes are mostly bonded to the fiber
with a variant of this system that had a chlorine where the amino group was.
Usually, there is just one ring, dye on one side, cellulose on other, the other
endgroups are H2. The killer for Formica is grape juice. For the reactive dyes,
Clorox bleach (but that usually kills the azo n=N groups of the dye, not the
covalent bond or the triazine ring). Shall I send you the formulas sketched out?
It's pretty neat. Happy New Year. Mary